Ink chamber doctor blades of the above type are commonly known from the printing technique because of their widespread use. An aspect of such ink chamber doctor blades essential to the printing trade is the sealing of the front ends of the ink chamber doctor blades against undesirable ink discharge. This involves both sealing the front end of the ink chamber formed within the ink chamber doctor blade and providing a sealing in the area of the two doctor blade knife ends and of the area of the outer circumference of the printing cylinder or the ink transfer roller located between these doctor blade knife ends, the latter sealing causing the more difficult problem. It has hitherto been conventional for known ink chamber doctor blades to close their front ends with respective rigid front end covers in the manner of a flange seal, which covers, however, leave open the section immediately adjacent to the outer circumference of the printing cylinder or the ink transfer roller. For this section an elastic plastic body is provided as a sealing element secured to the side of the front end cover pointing to the interior of the ink chamber doctor blade. The front side of the plastic body pointing to the outer circumference of the printing cylinder or the ink transfer roller is adapted to the roundness of the printing cylinder or the ink transfer roller; following this roundness are two inclined side flanks, the inclination of which is adapted to the alignment of the doctor blade knives. The rear side of the plastic body is usually straight-lined and forms a seat for securing the plastic body to the front end cover. The sealing is then effected in a manner such that the plastic body is clamped with a certain pre-tension between the front end cover securing it and the doctor blade knives abutting against its side flanks. In view of its elasticity the plastic body adapts itself to the surfaces of the doctor blade knives pointing to the interior of the ink chamber, and the plastic body adapts itself to the outer circumference of the printing cylinder or the ink transfer roller. Practical experience, however, has shown that, in operation, this adaptation will last only for a limited time; for after a certain operating time ink will penetrate and move on the side flank of the plastic body in the direction of rotation of the printing cylinder or the ink transfer roller, which ink will be thickened through the heat developing as a result of the friction between printing cylinder or ink transfer roller and plastic body and will collect more and more in the increasingly widening slot space between the side flank of the plastic body and the interior of the doctor blade. Moreover, the wear of the plastic body in its area of contact with the printing cylinder or the ink transfer roller cannot be effectively compensated, because the doctor blade knives prevent the plastic body from moving towards the printing cylinder or the ink transfer roller. Consequently, in this area the plastic body loses its sealing effect, and ink will gradually discharge to an increasing extent from the interior of the ink chamber outwards. Such ink discharge is undesirable and is partially even detrimental to the quality of the printed products or the usability of the printing machine. To avoid ink discharge, the plastic body must be replaced at relatively short intervals, which requires respective interruptions of the printing process and partial disassembly of the ink chamber doctor blade, which can only be done after preceding removal of the ink from the ink chamber. Finally, it is a drawback that the plastic body, through the forces exerted by its inclined side flanks on the interior of the doctor blade knives, pushes the latter out of their straight-line course. This deviation of the doctor blade knives from the desired straight-line course gives an enlarged doctor blade slot in the area of the doctor blade ends and thus leads to an increase in the ink supplied thereto in this section of the printing cylinder or the ink transfer roller. This gives irregular ink saturation in subsequent printing, which means a deterioration.